1. Field of the Invention
The present invention relates to a communication terminal, a communication method and a communication program, and more particularly to a communication terminal connectable to an IP network, a communication method executed in the communication terminal and a communication program.
2. Description of the Related Art
In recent years, IP telephones using IP (Internet Protocol) network such as the Internet in place of a public telephone network have emerged. IP network can be realized by a local area network using wireless communications (referred to as “wireless LAN” hereinafter). A mobile phone such as PDC (Personal Digital Cellular) or PHS (Personal Handyphone System) equipped with a communication circuit adapted to such a wireless LAN can be used as an IP telephone.
On the other hand, when a mobile phone is used as an IP phone, a wireless LAN (Local Area Network) using a radio wave as a communication medium is generally employed. Since the communicable range of the wireless LAN is relatively narrow, a user carrying a mobile phone cannot maintain the communication when moving outside the range where communication can be established.
Conventionally, a wireless phone device is known in which when identification means identifies that the device is out of service, a telephone number is input by operation means, so that said telephone number is stored in storage means, and when the identification means identifies that the device is in service after moving, call originating control means controls such that call originating means automatically makes a call to the telephone number stored in said storage means.
However, even with the conventional technique, a call cannot be established when a mobile phone is located outside the range of the wireless LAN. Even when the phone is located outside the range of the wireless LAN, if it is located within the communication range of the mobile phone, a call can be established using the mobile phone network. However, in order to connect to the mobile phone network, a user has to input the other party's telephone number or select it from a telephone book, which complicates the operation.